Hello,
In vb2_cma_put if buf->refcount is 0, cma_free is called.
But vb2_cma_put is usually called from munmap.
In my opinion cma_free should be called from VIDIOC_REQBUFS(0) not munmap.
BRs,
2010/9/9 Pawel Osciak <p.osciak@xxxxxxxxxxx>:
> Add support for the CMA contiguous memory allocator to videobuf2.
>
> Signed-off-by: Pawel Osciak <p.osciak@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> drivers/media/video/Kconfig | 5 +
> drivers/media/video/Makefile | 2 +
> drivers/media/video/videobuf2-cma.c | 250 +++++++++++++++++++++++++++++++++++
> include/media/videobuf2-cma.h | 25 ++++
> 4 files changed, 282 insertions(+), 0 deletions(-)
> create mode 100644 drivers/media/video/videobuf2-cma.c
> create mode 100644 include/media/videobuf2-cma.h
>
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index c2ea549..b63f377 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -65,6 +65,11 @@ config VIDEOBUF2_VMALLOC
> select VIDEOBUF2_GEN_MEMOPS
> tristate
>
> +config VIDEOBUF2_CMA
> + depends on CMA
> + select VIDEOBUF2_CORE
> + select VIDEOBUF2_GEN_MEMOPS
> + tristate
>
> #
> # Multimedia Video device configuration
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index 20d359d..4146700 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -128,6 +128,8 @@ obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2_vmalloc.o
> videobuf2_vmalloc-y := videobuf2-vmalloc.o \
> videobuf2-memops.o
>
> +obj-$(CONFIG_VIDEOBUF2_CMA) += videobuf2_cma.o
> +videobuf2_cma-y := videobuf2-cma.o videobuf2-memops.o
>
> obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
>
> diff --git a/drivers/media/video/videobuf2-cma.c b/drivers/media/video/videobuf2-cma.c
> new file mode 100644
> index 0000000..c51e5a8
> --- /dev/null
> +++ b/drivers/media/video/videobuf2-cma.c
> @@ -0,0 +1,250 @@
> +/*
> + * videobuf2-cma.c - CMA memory allocator for videobuf2
> + *
> + * Copyright (C) 2010 Samsung Electronics
> + *
> + * Author: Pawel Osciak <p.osciak@xxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/cma.h>
> +#include <linux/mm.h>
> +#include <linux/sched.h>
> +#include <linux/file.h>
> +
> +#include <media/videobuf2-core.h>
> +#include <media/videobuf2-memops.h>
> +
> +struct vb2_cma_conf {
> + struct vb2_alloc_ctx alloc_ctx;
> + struct device *dev;
> + const char *type;
> + unsigned long alignment;
> +};
> +
> +struct vb2_cma_buf {
> + struct vb2_cma_conf *conf;
> + dma_addr_t paddr;
> + unsigned long size;
> + unsigned int refcount;
> + struct vm_area_struct *vma;
> +};
> +
> +static void *vb2_cma_alloc(const struct vb2_alloc_ctx *alloc_ctx,
> + unsigned long size)
> +{
> + struct vb2_cma_conf *conf =
> + container_of(alloc_ctx, struct vb2_cma_conf, alloc_ctx);
> + struct vb2_cma_buf *buf;
> +
> + buf = kzalloc(sizeof *buf, GFP_KERNEL);
> + if (!buf)
> + return ERR_PTR(-ENOMEM);
> +
> + buf->paddr = cma_alloc(conf->dev, conf->type, size, conf->alignment);
> + if (!buf->paddr) {
> + printk(KERN_ERR "cma_alloc of size %ld failed\n", size);
> + kfree(buf);
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + buf->conf = conf;
> + buf->size = size;
> + buf->refcount++;
> +
> + printk(KERN_DEBUG "Allocated cma mem of size %ld at paddr=0x%08x\n",
> + buf->size, buf->paddr);
> +
> + return buf;
> +}
> +
> +static void vb2_cma_put(void *buf_priv)
> +{
> + struct vb2_cma_buf *buf = buf_priv;
> +
> + buf->refcount--;
> +
> + if (0 == buf->refcount) {
> + cma_free(buf->paddr);
> + kfree(buf);
> + }
> +}
> +
> +static unsigned long vb2_cma_paddr(void *buf_priv)
> +{
> + struct vb2_cma_buf *buf = buf_priv;
> +
> + return buf->paddr;
> +}
> +
> +static unsigned int vb2_cma_num_users(void *buf_priv)
> +{
> + struct vb2_cma_buf *buf = buf_priv;
> +
> + return buf->refcount;
> +}
> +
> +static void vb2_cma_vm_open(struct vm_area_struct *vma)
> +{
> + struct vb2_cma_buf *buf = vma->vm_private_data;
> +
> + printk(KERN_DEBUG "%s cma_priv: %p, refcount: %d, "
> + "vma: %08lx-%08lx\n", __func__, buf, buf->refcount,
> + vma->vm_start, vma->vm_end);
> +
> + buf->refcount++;
> +}
> +
> +static void vb2_cma_vm_close(struct vm_area_struct *vma)
> +{
> + struct vb2_cma_buf *buf = vma->vm_private_data;
> +
> + printk(KERN_DEBUG "%s cma_priv: %p, refcount: %d, "
> + "vma: %08lx-%08lx\n", __func__, buf, buf->refcount,
> + vma->vm_start, vma->vm_end);
> +
> + vb2_cma_put(buf);
> +}
> +
> +static const struct vm_operations_struct vb2_cma_vm_ops = {
> + .open = vb2_cma_vm_open,
> + .close = vb2_cma_vm_close,
> +};
> +
> +static int vb2_cma_mmap(void *buf_priv, struct vm_area_struct *vma)
> +{
> + struct vb2_cma_buf *buf = buf_priv;
> +
> + if (!buf) {
> + printk(KERN_ERR "No memory to map\n");
> + return -EINVAL;
> + }
> +
> + return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
> + &vb2_cma_vm_ops, buf);
> +}
> +
> +static void *vb2_cma_get_userptr(unsigned long vaddr, unsigned long size)
> +{
> + struct vb2_cma_buf *buf;
> + unsigned long paddr = 0;
> + int ret;
> +
> + buf = kzalloc(sizeof *buf, GFP_KERNEL);
> + if (!buf)
> + return ERR_PTR(-ENOMEM);
> +
> + buf->vma = vb2_get_userptr(vaddr);
> + if (!buf->vma) {
> + printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
> + vaddr);
> + ret = -EINVAL;
> + goto done;
> + }
> +
> + ret = vb2_contig_verify_userptr(buf->vma, vaddr, size, &paddr);
> + if (ret) {
> + vb2_put_userptr(buf->vma);
> + goto done;
> + }
> +
> + buf->size = size;
> + buf->paddr = paddr;
> +
> + return buf;
> +
> +done:
> + kfree(buf);
> + return ERR_PTR(ret);
> +}
> +
> +static void vb2_cma_put_userptr(void *mem_priv)
> +{
> + struct vb2_cma_buf *buf = mem_priv;
> +
> + if (!buf)
> + return;
> +
> + vb2_put_userptr(buf->vma);
> + kfree(buf);
> +}
> +
> +static const struct vb2_mem_ops vb2_cma_ops = {
> + .alloc = vb2_cma_alloc,
> + .put = vb2_cma_put,
> + .paddr = vb2_cma_paddr,
> + .mmap = vb2_cma_mmap,
> + .get_userptr = vb2_cma_get_userptr,
> + .put_userptr = vb2_cma_put_userptr,
> + .num_users = vb2_cma_num_users,
> +};
> +
> +struct vb2_alloc_ctx *vb2_cma_init(struct device *dev, const char *type,
> + unsigned long alignment)
> +{
> + struct vb2_cma_conf *conf;
> +
> + conf = kzalloc(sizeof *conf, GFP_KERNEL);
> + if (!conf)
> + return ERR_PTR(-ENOMEM);
> +
> + conf->dev = dev;
> + conf->type = type;
> + conf->alignment = alignment;
> + conf->alloc_ctx.mem_ops = &vb2_cma_ops;
> +
> + return &conf->alloc_ctx;
> +}
> +EXPORT_SYMBOL_GPL(vb2_cma_init);
> +
> +void vb2_cma_cleanup(struct vb2_alloc_ctx *alloc_ctx)
> +{
> + struct vb2_cma_conf *conf =
> + container_of(alloc_ctx, struct vb2_cma_conf, alloc_ctx);
> +
> + kfree(conf);
> +}
> +EXPORT_SYMBOL_GPL(vb2_cma_cleanup);
> +
> +struct vb2_alloc_ctx **vb2_cma_init_multi(struct device *dev,
> + unsigned int num_planes,
> + const char *types[],
> + unsigned long alignments[])
> +{
> + struct vb2_alloc_ctx **alloc_ctxes;
> + struct vb2_cma_conf *cma_conf;
> + unsigned int i;
> +
> + alloc_ctxes = kzalloc((sizeof *alloc_ctxes + sizeof *cma_conf)
> + * num_planes, GFP_KERNEL);
> + if (!alloc_ctxes)
> + return ERR_PTR(-ENOMEM);
> +
> + cma_conf = (void *)(alloc_ctxes + num_planes);
> +
> + for (i = 0; i < num_planes; ++i, ++cma_conf) {
> + alloc_ctxes[i] = &cma_conf->alloc_ctx;
> + cma_conf->dev = dev;
> + cma_conf->type = types[i];
> + cma_conf->alignment = alignments[i];
> + cma_conf->alloc_ctx.mem_ops = &vb2_cma_ops;
> + }
> +
> + return alloc_ctxes;
> +}
> +EXPORT_SYMBOL_GPL(vb2_cma_init_multi);
> +
> +void vb2_cma_cleanup_multi(struct vb2_alloc_ctx **alloc_ctxes)
> +{
> + kfree(alloc_ctxes);
> +}
> +EXPORT_SYMBOL_GPL(vb2_cma_cleanup_multi);
> +
> +MODULE_DESCRIPTION("CMA allocator handling routines for videobuf2");
> +MODULE_AUTHOR("Pawel Osciak");
> +MODULE_LICENSE("GPL");
> diff --git a/include/media/videobuf2-cma.h b/include/media/videobuf2-cma.h
> new file mode 100644
> index 0000000..557eeb0
> --- /dev/null
> +++ b/include/media/videobuf2-cma.h
> @@ -0,0 +1,25 @@
> +/*
> + * videobuf2-cma.h - CMA memory allocator for videobuf2
> + *
> + * Copyright (C) 2010 Samsung Electronics
> + *
> + * Author: Pawel Osciak <p.osciak@xxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation.
> + */
> +
> +struct vb2_alloc_ctx *vb2_cma_init(struct device *dev, const char *type,
> + unsigned long alignment);
> +void vb2_cma_cleanup(struct vb2_alloc_ctx *alloc_ctx);
> +
> +struct vb2_alloc_ctx **vb2_cma_init_multi(struct device *dev,
> + unsigned int num_planes, const char *types[],
> + unsigned long alignments[]);
> +void vb2_cma_cleanup_multi(struct vb2_alloc_ctx **alloc_ctxes);
> +
> +struct vb2_alloc_ctx *vb2_cma_init(struct device *dev, const char *type,
> + unsigned long alignment);
> +void vb2_cma_cleanup(struct vb2_alloc_ctx *alloc_ctx);
> +
> --
> 1.7.2.1.97.g3235b.dirty
>
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